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Unformatted text preview: Chromosomes, Mitosis and Meiosis Chapter 10 What is the significance of chromosomes in terms of information? Major carriers of genetic information 19thC Mendel - genetic factors 1880 Walter Fleming - seen during cell division 1903 Sutton and Boveri -carriers of genes Fig 10-1: Chromosomes Organization Genes cells informational units made of DNA Chromatin DNA and protein makes up chromosomes (eukaryotes) Chromosomes allow DNA sorting into daughter cells Summary In eukaryotic cells, DNA is wound around specific proteins to form chromatin, which in turn is folded and packaged to make individual chromosomes: Hu has ~46 chromosomes Roundworm has 2 chromosomes Most other animal species have 8-50 chromosomes/cell Prokaryotic Cells Contain circular DNA molecules e.g. E coli has 4 x 10(6) base pairs of DNA in one single circular DNA molecule Spans 10(3) x length of the cell Twisted and folded to fit ! Eukaryotic cells Have more DNA than bacteria Multiple chromosomes DNA is 10(3) x that in a bacterium Sperm contain 3 x 10(9) base pairs 1m long and fits into a nucleus that is 10um This much DNA has to be finely packaged into nucleus accomplished by...
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